diff mbox

linux-user: Fix definition of target_sigevent for 32-bit guests

Message ID 1472838001-1673-1-git-send-email-peter.maydell@linaro.org
State Accepted
Commit 17351c3f11e52101e1498ba03eec06fa5e4e713a
Headers show

Commit Message

Peter Maydell Sept. 2, 2016, 5:40 p.m. UTC
The sigevent structure includes a union with some fields which
are pointers. For the QEMU target_sigevent structure we must
represent these as abi_ulongs, not host function pointers.

This error was causing the compiler to believe it should 8-align
the _sigev_un union on a 64-bit host, which meant that the
code in target_to_host_sigevent() was looking at the wrong
offset to find the _tid field, and timer_create() would
spuriously fail with EINVAL.

This fixes the final loose end noted in LP:1042388.

While we're editing the structure, switch the 'int32_t' fields
to 'abi_int'; this will only matter for guests with non-standard
integer alignment like m68k.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

---
 linux-user/syscall_defs.h | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

-- 
2.7.4

Comments

Peter Maydell Oct. 4, 2016, 1:08 p.m. UTC | #1
Ping ?

thanks
-- PMM

On 2 September 2016 at 18:40, Peter Maydell <peter.maydell@linaro.org> wrote:
> The sigevent structure includes a union with some fields which

> are pointers. For the QEMU target_sigevent structure we must

> represent these as abi_ulongs, not host function pointers.

>

> This error was causing the compiler to believe it should 8-align

> the _sigev_un union on a 64-bit host, which meant that the

> code in target_to_host_sigevent() was looking at the wrong

> offset to find the _tid field, and timer_create() would

> spuriously fail with EINVAL.

>

> This fixes the final loose end noted in LP:1042388.

>

> While we're editing the structure, switch the 'int32_t' fields

> to 'abi_int'; this will only matter for guests with non-standard

> integer alignment like m68k.

>

> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

> ---

>  linux-user/syscall_defs.h | 16 ++++++++++------

>  1 file changed, 10 insertions(+), 6 deletions(-)

>

> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h

> index dbf6a38..f4417ee 100644

> --- a/linux-user/syscall_defs.h

> +++ b/linux-user/syscall_defs.h

> @@ -2618,15 +2618,19 @@ typedef int32_t target_timer_t;

>

>  struct target_sigevent {

>      target_sigval_t sigev_value;

> -    int32_t sigev_signo;

> -    int32_t sigev_notify;

> +    abi_int sigev_signo;

> +    abi_int sigev_notify;

>      union {

> -        int32_t _pad[TARGET_SIGEV_PAD_SIZE];

> -        int32_t _tid;

> +        abi_int _pad[TARGET_SIGEV_PAD_SIZE];

> +        abi_int _tid;

>

> +        /* The kernel (and thus QEMU) never looks at these;

> +         * they're only used as part of the ABI between a

> +         * userspace program and libc.

> +         */

>          struct {

> -            void (*_function)(sigval_t);

> -            void *_attribute;

> +            abi_ulong _function;

> +            abi_ulong _attribute;

>          } _sigev_thread;

>      } _sigev_un;

>  };

> --

> 2.7.4
Riku Voipio Oct. 7, 2016, 12:19 p.m. UTC | #2
On Tue, Oct 04, 2016 at 02:08:24PM +0100, Peter Maydell wrote:
> Ping ?


Applied, thanks.
 
> thanks

> -- PMM

> 

> On 2 September 2016 at 18:40, Peter Maydell <peter.maydell@linaro.org> wrote:

> > The sigevent structure includes a union with some fields which

> > are pointers. For the QEMU target_sigevent structure we must

> > represent these as abi_ulongs, not host function pointers.

> >

> > This error was causing the compiler to believe it should 8-align

> > the _sigev_un union on a 64-bit host, which meant that the

> > code in target_to_host_sigevent() was looking at the wrong

> > offset to find the _tid field, and timer_create() would

> > spuriously fail with EINVAL.

> >

> > This fixes the final loose end noted in LP:1042388.

> >

> > While we're editing the structure, switch the 'int32_t' fields

> > to 'abi_int'; this will only matter for guests with non-standard

> > integer alignment like m68k.

> >

> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

> > ---

> >  linux-user/syscall_defs.h | 16 ++++++++++------

> >  1 file changed, 10 insertions(+), 6 deletions(-)

> >

> > diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h

> > index dbf6a38..f4417ee 100644

> > --- a/linux-user/syscall_defs.h

> > +++ b/linux-user/syscall_defs.h

> > @@ -2618,15 +2618,19 @@ typedef int32_t target_timer_t;

> >

> >  struct target_sigevent {

> >      target_sigval_t sigev_value;

> > -    int32_t sigev_signo;

> > -    int32_t sigev_notify;

> > +    abi_int sigev_signo;

> > +    abi_int sigev_notify;

> >      union {

> > -        int32_t _pad[TARGET_SIGEV_PAD_SIZE];

> > -        int32_t _tid;

> > +        abi_int _pad[TARGET_SIGEV_PAD_SIZE];

> > +        abi_int _tid;

> >

> > +        /* The kernel (and thus QEMU) never looks at these;

> > +         * they're only used as part of the ABI between a

> > +         * userspace program and libc.

> > +         */

> >          struct {

> > -            void (*_function)(sigval_t);

> > -            void *_attribute;

> > +            abi_ulong _function;

> > +            abi_ulong _attribute;

> >          } _sigev_thread;

> >      } _sigev_un;

> >  };

> > --

> > 2.7.4

>
diff mbox

Patch

diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
index dbf6a38..f4417ee 100644
--- a/linux-user/syscall_defs.h
+++ b/linux-user/syscall_defs.h
@@ -2618,15 +2618,19 @@  typedef int32_t target_timer_t;
 
 struct target_sigevent {
     target_sigval_t sigev_value;
-    int32_t sigev_signo;
-    int32_t sigev_notify;
+    abi_int sigev_signo;
+    abi_int sigev_notify;
     union {
-        int32_t _pad[TARGET_SIGEV_PAD_SIZE];
-        int32_t _tid;
+        abi_int _pad[TARGET_SIGEV_PAD_SIZE];
+        abi_int _tid;
 
+        /* The kernel (and thus QEMU) never looks at these;
+         * they're only used as part of the ABI between a
+         * userspace program and libc.
+         */
         struct {
-            void (*_function)(sigval_t);
-            void *_attribute;
+            abi_ulong _function;
+            abi_ulong _attribute;
         } _sigev_thread;
     } _sigev_un;
 };